Computer security is an important aspect of many computer networks. As businesses and institutions become more connected and dependent on the Internet, the risk of attacks has also grown. Most of the intrusion detection systems (IDS) on the market today are capable of collecting different events on the network and displaying them.
FIG. 1 is a topology diagram of an example network. A firewall 100 protects the network from the Internet. Different sections of the network are connected to each other and to the Internet via various networking devices on the network, including routers, switches, firewalls, etc. A number of servers and hosts are connected directly or indirectly to some of these networking devices. An IDS 105 collects events associated with a part of the network by connecting with certain networking devices such as switches 110 and 115, or by tapping into connection links such as link 120. The IDS may also aggregate the data collected into some central location for later retrieval and analysis, as well as provide interface for accessing the data.
A security administrator or an authorized user can use the information collected from the network to determine the nature of any suspicious activities. For example, the security administrator may identify certain critical events, examine the data collected to trace the chain of events that are associated with the critical events in order to determine where the threats come from, and then decide what responsive actions to take. Making a reasonable assessment is a time and resource intensive process, and the amount of effort spent is very much dependent on the security administrator's knowledge and experience. Also, as the network becomes more complex, the amount of data collected can be too overwhelming to be processed manually. It would be useful to have a system that can facilitate the assessment process with greater intelligence, thereby reducing the amount of time and resource needed by the process.